When considering what packaging material is optimal for a piece of biological evidence there are two vital things to consider: degradation and contamination (1). Biological evidence collected from a crime scene is brought to the laboratory, however, immediate testing upon arrival is highly unlikely (2). Therefore, the packaging must be suitable for transportation as well as storage. During the storage phase, if improper packaging is utilized, degradation and/or contamination could occur. General forensic practice is to dry biological samples before packaging, then package the evidence in a paper (breathable) container. This study investigated the use of kraft stock envelopes, plastic bags, glassine envelopes, Tyvek envelopes, evidence/syringe tubes, knife pouches, and Cap-Shure® plastic swab caps to package wet blood and semen samples. The packaging materials were evaluated in a humidity study, degradation study, and transfer study to determine if the biological specimen would remain intact and contained within the packaging. In the humidity study, it was determined that the kraft paper, glassine paper, and Tyvek® allowed for the passage of moisture, enabling the enclosed sample to readily dry. The plastic bag, evidence tube, and knife pouch created a difference in relative humidity above 20%, thus increasing the ambient moisture concentration the samples were exposed to. In the degradation study, all samples were positive for their respective biological substance when tested with screening, presumptive, and confirmatory methods, however, bacteria were observed on samples that were packaged in plastic bags evidence tubes, and plastic caps. Additionally, only one sample, packaged in an evidence tube, yielded a DNA degradation index that implied degradation had occurred. The packaging materials were also tested to determine if the biological fluid would transfer through them, permitting cross-contamination. The kraft paper and one glassine paper did not provide a true barrier, as blood transferred through the envelopes onto a surrounding surface. The Tyvek®, knife pouch, and plastic bag all kept the wet blood contained within the package and no transfer to the surrounding surfaces occurred, although bloodstains on the interior of the Tyvek® and knife pouch could be visualized from the exterior. Overall, Tyvek® envelopes were determined to be an optimal packaging material for wet biological samples when compared to the other packaging materials used in this limited study due to their relative strength, ability to allow fluids to air dry and the lack of penetration of wet blood to the exterior surface.

No description available.

The state of Utah has sexual assault rates consistently higher than the national average. Following sexual assaults, victims are advised to seek health care services with evidence collected and packaged in sexual assault kits (SAKs). This large (N=1,874), retrospective study examined rates of sexual assault kit (SAK) submissions by law enforcement (LE) to the state crime laboratory for analysis at four sites in Utah with established sexual assault nurse examiner (SANE) programs on SAKs collected from 2010 to 2013. Variables of legal and extralegal characteristics in sexual assault cases were explored through GEE modeling to determine what factors predicted SAK submissions. For submitted SAKs, the length of time between the dates of assault and dates of submission were categorized and bivariate and multivariate analyses calculated to discover legal and extralegal characteristics affecting time of submission. The four study sites in Utah represented 40% of Utah LE agencies and 65% of the state’s population. Out of the 1,874 SAKs in the study, only 38.2% were submitted by LE to the state crime laboratory for analysis. When SAK submissions were examined based upon time between assaults and submission dates, 22.8% were submitted within a year of the assault and 15.4% were submitted more than a year after the assault following media and community pressure for LE agencies to submit SAKs in storage. Significant variability of SAK submission rates and the time submitted from the assault dates were found between the four sites. Site location was found to be the main determinant of whether or not SAKs were submitted. The lack of SAK submissions for analysis results in justice denied for victims and raises public safety concerns. The finding that the location in which the sexual assault occurred was the primary factor on SAK submissions represents an inequity of justice. / School of Nursing; / Nursing / PhD; / Dissertation;

abstract: Following a sexual assault, victims are advised to have a medical forensic exam and undergo a sexual assault kit (SAK) collection. The SAK is then held in police storage until it undergoes testing at a crime lab. Unfortunately, tens of thousands of SAKs in the United States remain untested. This thesis examines SAK submission by organizational decision makers in sexual assault case processing. Guided by Black's theory of law, this paper seeks to examine if white and minority victims systematically experience differential access to justice in terms of getting their respective SAKs submitted. Using data from a 1982-2012 Sexual Assault Kit Backlog Study in Los Angeles, California, the current study explores the relationship between race and SAK submission, legal (eg., case specific) and extralegal (eg., victim characteristics) variables across 1,826 backlogged SAKs and 339 non-backlogged SAKs. Results from the logistic regression analysis indicate that victims of nonstranger sexual assault are more likely to experience backlog of their SAK while victim race does not appear to affect SAK submission. Implications for theory, research and criminal justice practice are discussed. / Dissertation/Thesis / Masters Thesis Criminology and Criminal Justice 2016

To prosecute perpetrators of war crimes the International Criminal Court (ICC) must connect the physical actions of the offence and ‘most responsible’ offenders charged with planning, instigating and intent on carrying out crimes of genocide, crimes against humanity, war crimes and crimes of aggression. To date there has been no empirical study of the types of physical actions that make up this offence. There is no baseline knowledge to contextualize the offence and enable the ICC to make links between the actions on the ground and a perpetrator’s culpability. The purpose of this study was to produce the first multivariate model of war crime ground action using cases of war crime offences in Cambodia and Rwanda. The aim was to first identify a representative range offence behaviours, and secondly determine if ground actions could be differentiated into distinct forms of offending that indicate culpability, that is, knowledge and intent in carrying out the crime. Lastly, offence behaviours assessed to determine if external factors could account for variances in offender behaviour, and help the ICC account for variances in behaviour when making inferences from the models. This was achieved through content analysis, cluster analysis, smallest space analysis and multivariate analysis of variance. It was found that as many as 44 different killing and disposal methods are used over the course of war crimes in Cambodia and Rwanda and that these offence actions can be classified into four distinct themes of behaviour. The indentified conservative, expressive, integrative and adaptive theme demonstrates that offenders were committing war crime offences in different ways. Using the underlying theories attached to each mode the ICC can infer the culpability of an offender based on which theme their actions fall into. In this case offenders subscribing to the conservative theme are likely to reflect the planning and instigation components of a war crime and offenders whose actions fall within the expressive theme are likely to be using war crimes as a cover for personal gratification and gain. Finally it was found that variances of behaviour can be attributed to the geographical location and timing of the event, and helps the ICC target their investigations to locations and periods linked to conservative behaviour, the offender who performs it and thus their culpability. This study shows that multivariate analysis can contextualize ground actions in manner that allows the ICC to make informed decisions of perpetrator culpability during war crimes.

The decentralized nature of the Internet forms its very foundation, yet it is this very nature that has opened networks and individual machines to a host of threats and attacks from malicious agents. Consequently, forensic specialists - tasked with the investigation of crimes commissioned through the use of computer systems, where evidence is digital in nature - are often unable to adequately reach convincing conclusions pertaining to their investigations. Some of the challenges within reliable forensic investigations include the lack of a global view of the investigation landscape and the complexity and obfuscated nature of the digital world. A perpetual challenge within the evidence analysis process is the reliability and integrity associated with digital evidence, particularly from disparate sources. Given the ease with which digital evidence (such as metadata) can be created, altered, or destroyed, the integrity attributed to digital evidence is of paramount importance. This dissertation focuses on the challenges relating to the integrity of digital evidence within reliable forensic investigations. These challenges are addressed through the proposal of a model for the construction of a Forensic Evidence Management System (FEMS) to preserve the integrity of digital evidence within forensic investigations. The Biba Integrity Model is utilized to maintain the integrity of digital evidence within the FEMS. Casey's Certainty Scale is then employed as the integrity classifcation scheme for assigning integrity labels to digital evidence within the system. The FEMS model consists of a client layer, a logic layer and a data layer, with eight system components distributed amongst these layers. In addition to describing the FEMS system components, a fnite state automata is utilized to describe the system component interactions. In so doing, we reason about the FEMS's behaviour and demonstrate how rules within the FEMS can be developed to recognize and pro le various cyber crimes. Furthermore, we design fundamental algorithms for processing of information by the FEMS's core system components; this provides further insight into the system component interdependencies and the input and output parameters for the system transitions and decision-points infuencing the value of inferences derived within the FEMS. Lastly, the completeness of the FEMS is assessed by comparing the constructs and operation of the FEMS against the published work of Brian D Carrier. This approach provides a mechanism for critically analyzing the FEMS model, to identify similarities or impactful considerations within the solution approach, and more importantly, to identify shortcomings within the model. Ultimately, the greatest value in the FEMS is in its ability to serve as a decision support or enhancement system for digital forensic investigators. Copyright / Dissertation (MSc)--University of Pretoria, 2010. / Computer Science / unrestricted

No description available.

With criminal cases continuing to be exonerated across the United States, research must be done on the subject to advance current practices to reduce its occurrence in the future. This study combines county population data with the National Registry of Exonerations to analyze the contributing factors to wrongful convictions and the possible effect of population on their frequency. The objective of this study was to identify specific policy changes based on the five contributing factors to wrongful convictions that could be applied to population specific areas. The results yielded multiple patterns that are discussed thoroughly. These findings allowed the introduction of policy changes and proposals for future research.

Computer crimes have become very complex in terms of investigation and prosecution. This is mainly because forensic investigations are based on artifacts left oncomputers and other digital devices. In recent times, perpetrators of computer crimesare getting abreast of the digital forensics dynamics hence, capacitated to use someanti-forensics measures and techniques to obfuscate the investigation processes.Incases where such techniques are employed, it becomes extremely difficult, expensive and time consuming to carry out an effective investigation. This might causea digital forensics expert to abandon the investigation in a pessimistic manner.ThisProject work serves to practically demonstrate how numerous anti-forensics can bedeployed by the criminals to derail the smooth processes of digital forensic investigation with main focus on data hiding and encryption techniques, later a comparativestudy of the effectiveness of some selected digital forensics tools in analyzing andreporting shreds of evidence will be conducted.

Human hair profiling is an integral part of a forensic investigation but it is one of the most technically difficult subjects in forensic science. This thesis describes the research and development of a novel approach for the rapid identification of unknown human and other related keratin fibres found at a crime scene. The work presented here is developed systematically and considers sample collection, sample preparation, analysis and interpretation of spectral data for the profiling of hair fibres encountered in criminal cases. Spectral comparison of fibres was facilitated with the use of chemometrics methods such as PCA, SIMCA and Fuzzy Clustering, and the less common approach of multi-criteria decision making methodology (MCDM). The aim of the thesis was to investigate the potential of some vibrational spectroscopy techniques for matching and discrimination of single keratin hair fibres in the context of forensic evidence. The first objective (chapter 3) of the thesis was to evaluate the use of Raman and FT-IR micro-spectroscopy techniques for the forensic sampling of hair fibres and to propose the preferred technique for future forensic hair comparisons. The selection of the preferred technique was based on criteria such as spectral quality, ease of use, rapid analysis and universal application to different hair samples. FT-IR micro-spectroscopy was found to be the most appropriate technique for hair analysis because it enabled the rapid collection of spectra from a wide variety of hair fibres. Raman micro-spectroscopy, on the other hand, was hindered with fluorescence problems and did not allow the collection of spectra from pigmented fibres. This objective has therefore shown that FT-IR micro-spectroscopy is the preferable spectroscopic technique for forensic analysis of hair fibres, whilst Raman spectroscopy is the least preferred. The second objective (chapter 3) was to investigate, through a series of experiments, the effect of chemical treatment on the micro-environment of human hair fibres. The effect of bleaching agents on the hair fibres was studied with some detail at different treatment times and the results indicate a significant change in the chemical environment of the secondary structure of the hair fibre along with changes in the C-C backbone structure. One of the most important outcomes of this research was the behaviour of the fÑ-helix during chemical treatment. The hydrogen bonding in the fÑ-helix provides for the stable structure of the fibre and therefore any disruption to the fÑ-helix will inevitably damage the molecular structure of the fibre. The results highlighted the behaviour of the fÑ-helix, which undergoes a significant decrease in content during oxidation, and is partly converted to a random-coil structure, whilst the fÒ-sheet component of the secondary structure remains unaffected. The reported investigations show that the combination of FT-IR and Raman micro-spectroscopy can provide an insight and understanding into the complex chemical properties and reactions within a treated hair fibre. Importantly, this work demonstrates that with the aid of chemometrics, it is possible to investigate simultaneously FT-IR and Raman micro-spectroscopic information from oxidised hair fibres collected from one subject and treated at different times. The discrimination and matching of hair fibres on the basis of treatment has potential forensic applications. The third objective (chapter 4) attempted to expand the forensic application of FT-IR micro-spectroscopy to other keratin fibres. Animal fibres are commonly encountered in crime scenes and it thus becomes important to establish the origin of those fibres. The aim of this work was to establish the forensic applications of FT-IR micro-spectroscopy to animal fibres and to investigate any fundamental molecular differences between these fibres. The results established a discrimination between fibres consisting predominantly of fÑ-helix and those containing mainly a fÒ-sheet structure. More importantly, it was demonstrated through curve-fitting and chemometrics, that each keratin fibre contains a characteristic secondary structure arrangement. The work presented here is the first detailed FT-IR micro-spectroscopic study, utilising chemometrics as well as MCDM methods, for a wide range of keratin fibres, which are commonly, found as forensic evidence. Furthermore, it was demonstrated with the aid of the rank ordering MCDM methods PROMETHEE and GAIA, that it is possible to rank and discriminate keratin fibres according to their molecular characteristics obtained from direct measurements together with information sourced from the literature. The final objective (chapter 5) of the thesis was to propose an alternative method for the discrimination and matching of single scalp human hair fibres through the use of FT-IR micro-spectroscopy and chemometrics. The work successfully demonstrated, through a number of case scenarios, the application of the technique for the identification of variables such as gender and race for an unknown single hair fibre. In addition, it was also illustrated that known hair fibres (from the suspect or victim) can be readily matched to the unknown hair fibres found at the crime scene. This is the first time that a substantial, systematic FT-IR study of forensic hair identification has been presented. The research has shown that it is possible to model and correlate individual¡¦s characteristics with hair properties at molecular level with the use of chemometrics methods. A number of different, important forensic variables of immediate use to police in a crime scene investigation such as gender, race, treatment, black and white hair fibres were investigated. Blind samples were successfully applied both to validate available experimental data and extend the current database of experimental determinations. Protocols were posed for the application of this methodology in the future. The proposed FT-IR methodology presented in this thesis has provided an alternative approach to the characterisation of single scalp human hair fibres. The technique enables the rapid collection of spectra, followed by the objective analytical capabilities of chemometrics to successfully discriminate animal fibres, human hair fibres from different sources, treated from untreated hair fibres, as well as black and white hair fibres, on the basis of their molecular structure. The results can be readily produced and explained in the courts of law. Although the proposed relatively fast FT-IR technique is not aimed at displacing the two slower existing methods of hair analysis, namely comparative optical microscopy and DNA analysis, it has given a new dimension to the characterisation of hair fibres at a molecular level, providing a powerful tool for forensic investigations.